poppin/kernel/src/mem/heap/mod.rs
2024-09-02 17:51:10 +03:00

47 lines
1.7 KiB
Rust

//use core::{alloc::{AllocError, GlobalAlloc, Layout}, sync::atomic::{AtomicUsize, Ordering}};
//use x86_64::align_up;
pub const HEAP_START: usize = 0x40000000; // 0x40000000 - 0x40019000
pub const HEAP_SIZE: usize = 100 * 1024; // 100 KiB
// A simple allocator that allocates memory linearly and ignores freed memory.
//#[derive(Debug)]
//pub struct BumpAllocator {
// heap_start: usize,
// heap_end: usize,
// next: AtomicUsize,
//}
//impl BumpAllocator {
// pub const fn new(heap_start: usize, heap_end: usize) -> Self {
// Self { heap_start, heap_end, next: AtomicUsize::new(heap_start) }
// }
//}
//unsafe impl GlobalAlloc for BumpAllocator {
// unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
// loop {
// // load current state of the `next` field
// let current_next = self.next.load(Ordering::Relaxed);
// let alloc_start = align_up(current_next as u64, layout.align() as u64);
// let alloc_end = alloc_start.saturating_add(layout.size() as u64);
//
// if alloc_end <= self.heap_end as u64 {
// // update the `next` pointer if it still has the value `current_next`
// let next_now = self.next.compare_exchange(current_next, alloc_end as usize, Ordering::Relaxed, Ordering::Relaxed).unwrap();
// if next_now == current_next {
// // next address was successfully updated, allocation succeeded
// return alloc_start as *mut u8;
// }
// } else {
// panic!("OUT OF MEMORY");
// }
// }
// }
// unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
// // do nothing, leak memory
// }
//}